Question: $ -0.22\% \div (30\% \div -3\%) $
Solution: Convert each percentage into a decimal dividing by $100$ $ -0.00216 \div (0.3 \div -0.03) $ $ = -0.00216 \times (-0.03 \div 0.3)$ $ = (-0.00216 \times -0.03) \div 0.3$ $ = 0.0001 \div 0.3$ ${0}$ ${3}$ ${6}$ ${4}$ ${8}$ $\text{Shift the decimal 1 to the right.}$ ${6}$ $\text{How many times does }3\text{ go into }{6}\text{?}$ ${2}$ ${6}$ ${0}$ $-\vphantom{0}$ ${6}\div3={2}\text{ or }3\times{2} = {6}$ ${4}$ $\text{How many times does }3\text{ go into }{4}\text{?}$ ${1}$ ${3}$ ${1}$ $-\vphantom{0}$ ${4}\div3={1}\text{ or }3\times{1} = {3}$ ${8}$ $\text{How many times does }3\text{ go into }{18}\text{?}$ ${6}$ ${1}$ ${8}$ ${0}$ $-\vphantom{0}$ ${18}\div3={6}\text{ or }3\times{6} = {18}$ $0.0648 \div 0.3 = 0.216$ Convert the decimal into a percentage by multiplying by $100$. $0.216 = 21.6\%$